Hi Steve, again me (the damager)
Try this code using latest 2.3a library:
'$include:'saveimage.bi'
'$include:'saveimage.bm'
Give this a try and see if it fixes the issue without breaking anything else for you, Petr:
Down on line 1172 in SaveImage.BM (where the error message points to), change that line to the following:
index256 = _RGBA(_RED32(t), _GREEN32(t), _BLUE32(t), _ALPHA32(t), I256)
This corrects the issue you pointed out, and I don't think it'll break anything else for us -- though that is always a possibility since SaveImage has grown into such a complex interwoven series of routines which allows it to do all that it does now: export to multiple file types, dither colors, choose palettes, do compression, convert modes... SaveImage has grown a ton from its initial conception, and with each release, it gets a little more nit picky about making certain that *everything* is working the way it should be, or else it tosses those little annoying glitches for us.
Luckily, almost all the issues are just simple little things to tweak (like changing all these commands from _RED, _GREEN, _BLUE, _ALPHA to the _32 versions instead), and the more people who test and report the problems, the quicker I can go in and get them corrected. Many thanks for all your hard work testing the library out with all the various configurations that are possible with it nowadays! It truly helps. ;D